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	<title>Document</title>
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	<script type="text/javascript">
		//第一步，用户输入数字
		var num = parseInt(prompt("请输入数字"));
		//第二步，得到每一位。是我们自己研究的算法
		var baiwei = parseInt(num / 100);
		var shiwei = parseInt(num % 100 / 10);
		var gewei = parseInt(num % 10);
		//第三步，计算和并显示
		var sum = baiwei + shiwei + gewei;
		//显示
		alert(sum);
	</script>
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